1. Technical Field
This invention relates generally to an imaging apparatus wherein a plurality of cut sheets are stacked in a supply to be driven from the supply to be imaged, and more particularly to such apparatus wherein the sheets are at least partially returned to the supply during the imaging process.
2. Background Art
Copiers, printer, facsimile apparatus and similar imaging machines are often provided with a cut sheet tray from which sheets are fed, such as by a scuff roller. As used herein, the term "tray" shall include removable sheet holders and fixed bin sheet holders. The cut sheets may be used such as for originals to be reproduced or as receiver sheets to be imaged. In this specification and appended claims, the convention will be used that the sheets are stacked in the tray such that the "leading edge" of the sheets will be the first edge to emerge from the tray, and that the "trailing edge" of the sheets will be the last edge to emerge.
In a commercial thermal printer, the cut sheets travel downstream, leading edge first, from the tray to a printhead, where the sheets receive one of a plurality of color separation images. Before receiving each subsequent color separation image, the sheet is returned trailing edge first to a position upstream of the printhead. Because there is insufficient distance between the tray and the printhead for an entire sheet, the trailing edge of the sheet returns to a position inside of the cut sheet tray.
It has been found that, from time to time, jams may occur during the sheet-return process; particularly as the trailing edge of the sheet attempts to move past the leading edge of the stack of sheets remaining in the cut sheet tray.